Shear



Patented Dec. 19, 1933 .Lenin snella JolinJensen, Rockford,111.,.'assignorto Whitney. Metal lTool Company, Rockford; lll.,` acorporation of Illinois r.

*Appli'eatin e .rune as; 1931. 1 serial nq. 547.585

roiaims. l(o1. 164-46) blade is pivotedf. adjacent. tok the rear orIlinner end of the, throat Yof the shear." e e An important object ofthepresent invention is to. provide suchda shear having new andiml e provedactuating. mechanism whereby thev for- Yframe.

ward ends of the shear blades may be used'to Vperform slitting, notchingorliesimilar operations upon the edge of the work with the work sopositioned as to aiord the operator an unobstructed view ofthepointofcut.` e. i e. j

, Another object .is to provide a shear of this character having bladesof novel form arranged toV facilitate the cutting of slits lor notchesof accurately predetermined yextent in the edgeh'cf aworkpiece. e

Other objects and advantages will becomejapparentl from the followingdescriptionftaken in connection with the accompanying drawing in which:j

Figure f1 is a side'elevationalview off a shear Yembodyingcertainieatures of the invention. 11

Fig. 2 is a front elevational 'viewoffthe ,shear shown in Fig. l asviewed from theright hand side.` y

^ Fig. 3 is a fragmental portion of Fig. l showing the shearequippedwith another type of shear blade.

Fig. 4 is an end view of the shear bladesshown in Fig. 3.

Generally considered,

which the movable blade is pivoted on the frame near the inner `end ofthe throat, togetherwith powerful toggle means for moving the swingingblade, which means acts between the frame and, the free end of theswinging blade and is opn"` erated by aneccentric device mounted in theReferring more particularly tothe drawing the invention is herein shownas embodiedin a shear comprising an elongated base frame 10 having atits rear end (left hand end in Fig. l) an integrally formed portion orarm l1 extending upwardly and forwardly to form a throat 12 openingforwardly of the frame l0. Adjacent to its point of junction with thebase 10, vthe arm 11 is offset laterally as will be seen at 13 in Fig. 2so asto permit a lever le, pivoted at l5 adjacent the rear end of theframe, to be `moved downwardly across the throat l2 and past the upperedge of the base l0 which defines the lower side of the throat l2.`

The lever 14 serves as a carrier for a movable theinvention as herein vshown comprises a manually operable shear inr yshear blade lliwhich issecuredjto the'lerver4 Ascrews 17, and in its downward movement thelever` moves Lthe blade "16 'into operative relation to a stationaryshearV blade i8 secured by screws 19 tothe base 10,. 'I n u Y Thestationary shear` blade "1e is. in the embbdi ment shown fin Figs.V 1f,and 2forr`n`ed `with?.a straightshearing edgeZO located -a slightdies".-` tance above the lower edgeof the throat 12, while theinovableshear-blade has` a curved edge'. l21l fso 4as Ato adapt the blade io1rstarting operation at 'anypoint in'itslengtln` e i `lt isjdesirableinthepe `formanceof such a notching or slitting .operation toA make the cutgradually and' at a uniform rate soas to 4permit accurate determinationof the length ofjthe With thisfin view the present shear provides forrthe application .oiV the operating forcewatfthe ,forward end of amovable blade'lG bypowerful actuating. means operating'atitsmaximumjefinciency near the end ofthe cutting stroke." rThis meansinv theform 'shown comprisesha toggle acituator operating directlybetween the arm 11 and the. free end of 'the` lever lli'landvl'operatedby..

means of an eccentric device Vmounted inthe arm 11 rearwardly of thetoggle actuator.

, They-toggle actuator preferably comprises a at their other ends to theends ofthe arm 11 and @here The eccentric device employed to' operate.toggle links 23 comprises a shaft 26 mounted in antifriction bearingsinthe arm '11, rearwardly of the toggle-links, and having at one endthereof 4an operating handle 2'7 for rotating the shaft.

At its other end the shaft VZtlhas a crank 28 upon which a link 29 hasone' of its ends pivoted. The otherend of the link is` connected to thetoggles 23 throughthe medium of the bolt! which provides the pvot'Zd.

'en al;

The link 29 is so proportioned that the toggies 23 are in their extendedpositions when the crank 28 is positioned to movev transversely of thepath of movement of the pivot 24, so that a maximum power multiplicationof both the` eccentric deviceA Vand the toggle means is obtainedsimultaneously and at the end of the working stroke of thev shear. Inthis relation the crank 28 and the link 29 constitute vin effect asecond toggle. This enables the operator to perform a'relatively shortslitting operation adjacent the ends oi the shear blades 16 and 18 wherethe operation of the shear is clearly visible. Furthermore, clue to thegreat power multiplication, the cutting operation may fore, may beterminated accurately.

Such a slitting or notching operation may further be facilitated byequipping the shear with blades arranged to shear progressively from theforward end ofthe throat 12 toward the rear end of the throat. Thusasshown in Figs. 3 and 4 of the drawing, upper and lower shear bladesand 31 are provided adapted particularly for short cuts andv arranged inthe lowermost posi- Vtion Vof the lever 14 to bespaced apart in theinner portion of the throat 12 as indicated at 32.

in Fig. 3. Adjacent their outer ends (the right hand ends in Fig. 3) theblades are formed so as to start the shearing operation and shearprogressively toward the inner end of` the throat. This is accomplishedin the present instance by forming similar projecting portions 33 onboth of the blades. These projecting portions 33 form oppositelyextending points at the outer ends of the two shear blades and sloperearwardly from the points at relatively steep angles as indicated at34. Rearwardlyof the sloping edges 34 the blades are provided withgradually sloping edge portions 35 which merge with the rear edgeportions of the blades. Thus when the upper blade 30 is lowered thepointed ends 33 of the blade first contact the work and in such contactmay be accurately positioned. The two points 33 then pierce theiworkpiece and the shearing oper- 'ation progresses rearwardly of the shearand toward the rear edge of the work.

It willrbe noted that the steep angle 34 provided. yadjacent tothef'orward end of the Vprojecting portions 33 causes theshearingoperation .to progress'quiteslowly as the work is being pierced,andthereafter the edges 35 come into play so that the shearing operationprogresses more rapidly as the actuating mechanism of the shearapproaches its point 'of maximum power multiplication. Thus the form ofthe shear blades 30 and 31`isV coordinated with the variation in theAeffectiveness ofthe toggle actuator .f g and performance of theslittingoperation is facilitated. Y Y

I claim as my invention: Y n "1.4. A shear comprising a stationarymember and a'movable member pivoted thereto, means for actuating saidmovable member and a pair of cooperating shear blades secured on saidmembers, one of said blades having a portion adjacent to the free end ofsaid movable member arranged in relative approaching movement of theblades to cause shearing of the work progressively from the free end ofsaid movable member toward the pivot thereof. y

2. A shear comprising a stationary frame, a lever thereon, means formoving said lever, and cooperating shear blades on said frame and leverformed with projecting portions adjacent the free end of said leverarranged in relative approaching movement of the blades to start ashearing cut adjacent the free end of the lever and cut progressivelytoward the pivot of the lever.

3. A shear comprising a base having a lower portion and an overhangingstationary arm eX- tending upwardly and forwardly from the rear Vend ofsaid lower portion to provide a forwardly opening substantiallyhorizontal throat, a lever j pivoted on said base' adjacent to therearend of said throat and extending'forwardly along said arm, cooperatingshear blades Hired on said lever and vsaid lower portion of thebase,said blades being formed at their forward ends with portions projectingtoward each other whereby, in downward movement of said lever, to starta shearing out at the forward ends of said blades and cut progressivelyrearwardly of the blades, and means acting between the forward ends ofsaid arm and said lever for moving said upper shear blade.

' 4. A shear comprising a stationary blade, a cooperating movable bladehaving one end pivoted, one of said blades at the end adjacent the freeend of said pivoted blade having a point adapted to start the cuttingoperation when the pivoted blade is moved toward the stationary i blade,the-shearing edge forming said point being sloped at a relatively largeangle transversely of the blade on which it is formed and merging withan edge portion sloping at a less angle whereby to shear more rapidlytoward the pivot after the cutting operation has been started.

JOHN JENSEN. l

